Private jets emitted an estimated 19.55 million tonnes of CO₂-equivalent in 2023, according to an analysis of 3.57 million tracked flights. That number is a floor, not a ceiling: the underlying data includes empty repositioning flights that carry no passengers, and a meaningful share of flights are missing entirely.
An advocacy group drawing on the same tracking data argues that a large share of private flights are empty repositioning legs. Every one of those legs burns fuel and shows up in the total without any trip-purpose field to flag it.
Private jets don’t just fly when someone rich wants to go somewhere. They fly to pick up that person, and they fly back after dropping them off.
Those empty legs are called repositioning flights, and they’re already inside the most widely cited private jet emissions total. The number you’ve seen — 19.55 million tonnes of CO₂-equivalent in 2023 — includes every one of those no-passenger trips, because tracking data records a movement, not a motive.
Yet that published figure is almost certainly an undercount. The estimate leaves out ground-based sources and some flights entirely. This article looks at where the gaps are, and why the real climate cost of private aviation is higher than the headline suggests.
Repositioning flights are already in the total, but nobody can see them
The estimate came from a 2025 analysis of private flight records using Spire Aviation’s global ADS-B trajectory data — the same kind of transponder signals that flight trackers use to show jets on a map.
When a jet repositions to pick up a client, its transponder broadcasts the same departure, arrival, and aircraft-type fields as any other flight. Nothing in that feed says the cabin is empty.
An advocacy group drawing on the same underlying data claims that 41% of all private flights are empty repositioning legs. That’s a striking number, and it’s worth treating cautiously: it comes from a summary that labels those flights “pure emissions, zero passenger value.” But the core point stands regardless of the exact percentage — empty flights burn the same fuel as full ones, and they’re indistinguishable in the data.
You can see a jet move from Teterboro to Van Nuys. You cannot see whether anyone was aboard.
That ambiguity matters for every emissions chart you’ve seen. The core problem is a data gap: a study built on these signals has no way to tell an empty positioning leg from a flight with passengers. The published total treats both the same because, from an emissions standpoint, they are the same.
Some flights never made it into the data at all
The undercount isn’t just about empty legs you can’t see. The ICCT analysis behind that total notes that 7.1% of detected flights had no recorded departure airport. That means the researchers could identify a movement but couldn’t fully place it — and some flights may be missing from the dataset entirely.
Then there’s everything that happens on the ground. The ICCT scope is explicitly limited to fuel burned in flight.
Taxiing, ground vehicle access, and airport operations around private terminals sit outside the estimate. No major study has standardized how to count those sources, so they remain invisible in the published totals.
The regulatory net misses most private flights, too
Even when private jets burn measurable amounts of fuel, many of them escape mandatory carbon pricing. The EU Emissions Trading System excludes non-commercial operators emitting less than 1,000 tonnes of CO₂ per year. Commercial operators fall outside if they run fewer than 243 flights in any four-month period or emit less than 10,000 tonnes per year.
The European Commission has spelled out the reason in writing: including those operators would impose a “disproportionate administrative burden.” That’s a policy choice, not an oversight. And because empty positioning legs are included in an operator’s emissions total, the exemption covers them too.
Why a flight with nobody aboard looks identical to any other
ADS-B, or Automatic Dependent Surveillance–Broadcast, is a safety technology. An aircraft’s transponder broadcasts its position, altitude, and identifier — along with departure and arrival points — so air traffic control and other aircraft can see it. Environmental researchers repurpose that data to count flights and estimate fuel burn.
What the transponder does not broadcast is a passenger manifest.
It doesn’t know or care whether the cabin holds eight executives or nobody. For an emissions model, that’s a critical blind spot: every leg gets the same per-flight fuel calculation, so a repositioning trip to collect a customer and a paid flight to the Caribbean both enter the total identically.
The data tells you the jet moved. It doesn’t tell you why. Until tracking platforms or operators voluntarily flag repositioning legs, any published private jet emissions figure is a floor built on movement alone.
What the undercount means for travelers and policy
If you’re using a carbon calculator to compare travel options, treat private jet emissions as conservative. The published figures exclude ground operations and miss some flights, so the real impact per passenger is higher than any calculator currently shows.
There’s also a strange inversion in the market: empty legs are often sold at steep discounts — roughly 25% to 75% off normal charter rates, according to SkyAccess. A cheaper flight doesn’t burn less fuel. The atmosphere doesn’t offer a frequent-flyer discount.
Watch for two developments. First, regulators may eventually require reporting of ground-based emissions and repositioning flights.
Second, if empty-leg brokers continue to advertise those trips as a bargain, they may inadvertently make the undercount more visible. The data exists; it just hasn’t been connected to the accounting yet.
Questions? Answers.
How much CO2 do private jets emit?
An ICCT analysis of 3.57 million tracked flights estimated private jets emitted 19.55 million tonnes of CO₂-equivalent in 2023. This figure covers direct in-flight fuel use only and may miss some flights entirely.
How much does a single private jet flight emit?
The 2023 global estimate for the sector works out to roughly 5.5 tonnes of CO₂-equivalent per tracked flight, counting only fuel burned in flight.
How much can charter customers save by booking an empty-leg flight?
Empty-leg listings are often discounted by roughly 25% to 75% relative to full charter rates, according to marketplace data. The aircraft burns the same fuel as a full charter; only the price changes.
Why do published private jet emissions estimates miss some flights?
In the ICCT dataset, 7.1% of flights lacked a recorded departure airport, and some flights may be missing entirely. The analysis also excludes ground-based emissions like taxiing and vehicle access, so the published total understates the sector’s full footprint.
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